1. Field of the Invention
The present invention concerns a process for preparing alkali metal periodates from alkali metal iodates.
2. Description of the Prior Art
Alkali metal periodates have been prepared in the prior art by the following methods.
1. The treatment of periodic acid with an alkali metal hydroxide. The periodic acid is conveniently prepared by the electrolytic oxidation of iodine.
2. Sodium iodide can be converted to sodium periodate by reacting the iodide with sodium oxide in the presence of oxygen.
3. Sodium iodide can also be converted to sodium periodate by reacting the iodide with sodium hydroxide in the presence of oxygen.
4. Sodium iodate can be converted to the periodate by contacting the iodate with sodium hydroxide in the presence of chlorine or bromine.
Periodates when in the mono-or dibasic form readily oxidize propylene to its various oxidation forms including propylene oxide thereby converting the periodate to the iodate. It is therefore desirable to provide a method for converting the iodate to the periodate so that it can be employed to oxidize propylene. Such a process for oxidizing propylene and other olefins is described in copending application Ser. No. 834,609, now U.S. Pat. No. 4,120,877 by William P. Coker and Robert E. Lane, Jr. titled "OXIDATION OF OLEFINS TO OXIRANE COMPOUNDS WITH PERIODATE COMPOUNDS" filed simultaneously herewith (Sept. 19, 1977)
While the periodate compounds prepared herein by the present invention are in the tri-, tetra- or pentabasic state which are ineffective in oxidizing olefins to the corresponding epoxide, another copending application Ser. No. 834,610, now U.S. Pat. No. 4,134,967 by James E. Hillis and William P. Coker titled "PROCESS FOR PREPARING ALKALI METAL MONO- AND DIBASIC PERIODATES" filed simultaneously herewith (Sept. 19, 1977) provides a method for converting the tri-, tetra-, or pentabasic periodates to the mono- or dibasic state which are effective in oxidizing olefins.